In the 1890s, a businessman in Boise, Idaho, had a “hot” idea: Use the geothermal water at Kelly Hot Springs to create a hot-water bathing resort. With design help from architect John C. Paulson, banker C.W. Moore built The Natatorium Resort, the centerpiece of which was a 125-foot swimming pool that was 98 degrees year-round. But Moore didn’t stop with the resort—he also heated his Victorian mansion with geothermal water and soon convinced many affluent neighbors to do the same.
Today, the city of Boise is home to the largest municipally operated geothermal heating utility in the country, with more than 20 miles of pipeline warming over six million square feet of building space throughout the city. The system delivers naturally heated water at a toasty 177 degrees through this extensive network of pipes, providing heat to buildings like City Hall and the local YMCA, melting snow from sidewalks—and, yes, heating what is now a city recreation pool at the former Natatorium.
Across the country, more towns and cities are following Boise’s lead: Turning to geothermal energy in heating and cooling networks that serve entire neighborhoods, city blocks, campuses, and communities. Rather than powering one building at a time, these systems provide heating and/or cooling to multiple homes or businesses together. The many existing or in-progress systems nationwide span diverse locations, coalitions, climates, and geographies—illustrating the truly nationwide versatility of this efficient heating and cooling solution.
Geothermal District Heating and Cooling Nationwide
Klamath Falls, OR is home to another long-standing geothermal district heating and cooling system. The city started tapping geothermal heat in the early 1990s, and the system now serves 23 commercial, non-profit, and government facilities. The standout success for the Klamath Falls system is its geothermal sidewalk and bridge snow melt systems. By tapping into the geothermal reservoir below the town, which ranges from 200–220 degrees, the utility circulates hot water through a district heating loop and heat exchanger to ensure safe conditions for pedestrians and drivers.
In the academic sphere, numerous universities and colleges are using or developing community geothermal solutions. One example is Ball State University which pioneered the largest ground-source, closed-loop district geothermal energy system in the nation. This innovative system involves drilling approximately 3,600 boreholes across campus and seamlessly integrating them into the landscape. The project has created an estimated 2,300 direct and indirect jobs, and once fully operational, Ball State will be able to efficiently heat and cool 47 buildings—resulting in $2 million in annual savings—and shutter the university’s aging coal-fired boilers, reducing the campus carbon footprint by nearly half. The project was funded in part by a $5 million DOE grant under the American Recovery and Reinvestment Act in 2009.
Not all district-scale systems are as large as Ball State’s; they all bring something unique to the mix. For instance, the Preservation for Affordable Housing’s community geothermal pilot project at Barry Farm Redevelopment in Washington, D.C., announced in Fall 2023, aims to replace conventional fossil fuel systems with cost-effective geothermal district heating and cooling. This pilot project will be D.C.’s first comprehensive community heat pump system, serving residential apartments as well as retail and service spaces, setting a standard for energy goals and resilient communities in the area.
Not all district-scale systems are as large as Ball State’s; they all bring something unique to the mix. For instance, the Preservation for Affordable Housing’s community geothermal pilot project at Barry Farm Redevelopment in Washington, D.C., announced in Fall 2023, aims to replace conventional fossil fuel systems with cost-effective geothermal district heating and cooling. This pilot project will be D.C.’s first comprehensive community heat pump system, serving residential apartments as well as retail and service spaces, setting a standard for energy goals and resilient communities in the area.
Numerous other communities and organizations are taking advantage of district-scale geothermal heating and cooling, including Brown University; Notre Dame; the First Zero Energy Capable Community in Austin, TX; Framingham, MA; and New York City—demonstrating the versatility and nationwide appeal of using the “heat beneath our feet” to meet community energy needs.
DOE's Role in Advancing District Heating & Cooling
The U.S. Department of Energy’s (DOE) Geothermal Technologies Office (GTO) has also been at the forefront of innovation in and adoption of geothermal heating and cooling systems at community, district, and university scales. A flagship of these efforts is GTO’s Community Geothermal Heating and Cooling Design and Deployment (CommGeo) initiative, which is supporting 11 community coalitions in 10 states to plan and design community-scale geothermal heating and cooling systems.
The CommGeo initiative’s project design phase ranged from a direct-use geothermal district heating and cooling system in remote Nome, Alaska, to a shared community geothermal network aiming to serve more than 100 multi-family and single-family residential buildings in Chicago, Illinois. The CommGeo projects are also using a collaborative approach, designed to ensure community needs are represented and job training is developed for local workers. Not only will these projects serve their own communities; the five that GTO selected to install their designs will also provide case studies that can be replicated nationwide so other cities and towns can benefit from geothermal heating and cooling.
GTO has other initiatives to expand the use of geothermal heating and cooling nationwide, including analysis to quantify the grid and emissions impacts of geothermal heat pumps and outreach tools to help communities understand geothermal energy.
The growing interest in community- and district-scale geothermal heating and cooling systems represents a notable success in moving the country towards a more resilient energy future for all Americans. Through innovative projects, collaborative efforts, and targeted investments, GTO, its partners, and communities and campuses nationwide are blazing a path to widespread adoption of geothermal technologies—in turn, advancing energy solutions, enhancing community resilience, and fostering economic development nationwide.
To learn more about GTO's work in geothermal heating and cooling, explore GTO's Geothermal Heating & Cooling page, CommGeo initiative page, Low Temperature & Coproduced Resources program page, and Geothermal Heat Pumps page.
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